Hey, good to have you here!
I can give you some feedback indeed - this morning I decided to give Manabi Reader a try. I got some popup information about tracking my Kanji progress, so I went to that page to see how it works. There was a big red button “Unlock Kanji Progress Tracking” so I clicked it. I was asked to create an account. Usually I’m really wary about creating accounts and giving away my data, and more often than not, I’d prefer to not create an account despite missing out on some functionality.
But here I thought, well, fair enough, they probably need a place to store my Kanji progress in. So I created the account. Only to discover then that I need to pay for the tracking! So I gave you my data and in return got nothing.
My standard reflex at that point would be to just delete the app and not come back again.
I’m still there 
and I’m even telling you this story. This was my very first interaction with the app, and I found it to be really unpleasant. Maybe I’ll get to the app again tomorrow… let’s see.